These sensitive ultraviolet detectors can sense gases, flames

Physicists have fabricated crystalline photodetectors that can sense ultraviolet light, but that are transparent to visible light1.

The photodetectors, made of interconnected crystals of methylammonium lead chloride, can also be used to make sensors for detecting pollutant gases and flames.

Methylammonium lead chloride is a common semiconductor whose ultraviolet-detecting potential is yet to be explored.

Osman Bakr and his colleagues from King Abdullah University of Science and Technology (KAUST), Saudi Arabia, and University of Toronto, Canada, designed a ‘crystal-growth reaction’ that allows the growth of single crystals of methylammonium lead chloride. The single crystals then merge and give rise to a crystalline film of interconnected single crystals.

The scientists probed the optical and electrical properties of the crystals. And besides being only sensitive to ultraviolet light, the crystals generated high photocurrent with a fast response time of 1 millisecond.

In addition, sensors made of the crystalline detectors showed much higher sensitivity and faster response time than those of thin-film detectors, according to the scientists.

“By exploiting their sensitivity to ultraviolet light, the crystalline detectors could potentially be used for secure space-to-space transmission and various astronomical studies,” says Bakr.